Update constants.py

constants.py

@@ -112,3 +112,5 @@ DEMO_LIST = [
     {"title": "Search/Replace Example", "description": "Generate HTML first, then ask: 'Change the title to My New Title' or 'Add a blue background to the body'"},
     {"title": "Transformers.js App", "description": "Create a transformers.js application with AI/ML functionality using the transformers.js library"}
 ]
+```html
+<!-- index.html content here -->